Correction of blade cutting
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Joined: February 06, 2004
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Correction of blade cutting
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Posted on Thu Jun 26, 2014 9:44 pm
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I am having trouble with my lathe saw cutting. The beginning of the cuts are good. They look like this ][. But after an inch or so of cutting, the cuts begin to look like //. Except more slanted.
This is my setup
Any advise would be great.


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Joined: December 22, 2007
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Posted on Fri Jun 27, 2014 12:16 am
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It sounds like the blade may be moving to one side or the other as it cuts, rather than down the center. This can happen with very hard metals like stainless, titanium, or niobium especially if there is any room for the coil to shift while being cut. Adjusting the speed of the blade may help.


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Posted on Fri Jun 27, 2014 5:38 am
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I'd suggest trying to secure your wooden setup to your lathe's cross-feed mechanism rather than trying to freehand it.


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Posted on Fri Jun 27, 2014 10:07 am
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i've had the same problem before. it seems to happen because of a few reasons. the slant always occurs in the direction of the coil spin. each ring's spin slightly pushes the blade to one side. like lorraine said, it happens mostly with harder metals. the constant pushing of the coil through the blade never allows the blade to straighten out. the more friction that is created the higher the slant.

to fix, try all or some of these ideas that have worked for me. if you can adjust the blade slant, adjust it with a sightly opposite slant to the coil. try using an oil base lubricant when cutting to minimize friction. push 5-10 rings through at a time and then take the pressure off the coil to allow the blade to straighten out after each set (this requires a set up like the ringinator with springs holding the coil with tension to the cutting plate so the coil does not come off of the blade). also, try to push the coil with minimal force through the saw. drop your rpm's to 200 or less for hard metals.



Joined: February 06, 2004
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Posted on Fri Jun 27, 2014 2:36 pm
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I will try the cutting 5 rings at a time. I run the blades at about 100 RPMs (my stainless is 3/4 hard). As of right now I am using mineral oil as a lubricant. Can you suggest a better but inexpensive product?

I think I will try making a new guide block also. the one in the picture is not the current one.


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Joined: May 20, 2014
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Posted on Fri Jun 27, 2014 3:42 pm
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0. Inspect the Jig and lathe for loose connections, improper angles, etc.

1. Secure the Jig to the lathe. Use screws.

2. Make sure that the cut rings fall into a collection area and are not pushed out of the jig by the coil. This is also important for the tiny metal dust that results from cutting.

3. Inspect the blade using a magnifying glass if necessary to inspect the condition of the teeth or diamond coating. Use slower speed and cut slow and steady.


Any machine/gun oil should work as lubricant, but if if can get specialized lubricant for metal cutting, buy that.
You need to apply lubricant directly to the rings that are going to get cut, just before they do get cut, otherwise the heat will burn the oil and the wood will absorb it.
You can do something "MacGyvery" with surgical tubing and feed lubricant right at the cut.

You should have used a bisected metal pipe so the rings would not touch the wood. This would have prevented the lubricant for being absorbed by the wood and the rings would slide more easily. Metal would also act as a heat-sink, preventing your coil for heating too much, but, heated metal + wood = carbon monoxide.

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Posted on Sat Jun 28, 2014 3:29 am
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First suggestion, replace the wooden block. Wood wears/compresses quickly under those sorts of conditions, if those are pine 2x4s then chances are the inner channel near the blade is larger (from being compressed by the coils side to side torsion while cutting) which quickly skews the coils position, if you have a set of long feeler gauges you could verify this.

There is also a good chance the block is twisting if the only bolt securing it is that single central one, regardless of how tight you may have secured it. A single bolt will find a way to twist even if it's just a little. A small strip of 1/2 inch plywood screwed to the bottom of the block that's cut to fit that inner channel on the lathe would probably help.

To echo what Spartan1388 said, Where are your cuttings going? I can't see any sort of exit for them so I'm guessing they are falling on the coil/inside of the channel and adding friction to the coils movement in addition to the above mentioned channel wear issue. Trimming the back end of the channel so the rings fall away just a little after the blade will reduce the chances of cut rings creating a blockage or adding resistance. Drill a larger hole from the bottom going up towards the blade on a 45, creating a chute for the rings to fall down. Also gets rid of the cuttings at the same time.

While a steel block with a hole through it won't wear out quickly the issue of cuttings jamming up the channel are still quite likely maybe even worse without some sort of exit for the cuttings.

Instead of the wood or metal block that the coil passes through, I was thinking of a channeled steel mandrel (akin to Spartan1388's bisected pipe) running parallel to the blade that matches the ID of the coil which would sit just below the blade secured at both ends that the coil slides on. With a mandrel the coil will slide easily on it and the cuttings fall away as each ring is cut. Put it on a sliding track and all your set.

Mineral oil is pretty thin, unless you're bathing the coils in it it's probably not doing much and chances are most of the oil is being sucked up by the wood, what little is left on the coil probably burns off pretty quickly, you are cutting 3/4 hard stainless. I use wax for my saw cutting (by hand), wax at least stays in place until the coil heats up at the cut location. For myself, wax (just a bunch of melted household candle ends) works much better than mineral oil but maybe someone else has a better suggestion for a thick yet cheap lubricant.


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Posted on Sat Jun 28, 2014 1:47 pm
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I also use lathes to make my rings from stainless. I put a knob on the hand-wheel of my midi wood lathe to hand crank coils, then cut them on the metal lathe. I used HDPE to make a set of guide blocks with holes drilled in 1/64th increments. They are about 1" x 1-1/2" x 3" each, with a rabbet on one side so they fit in the tool holder on the traveling cross-slide. The coils pass though vertically and collect in a plastic bin. I use paste way for lube.

All that said, I still get some slanted cuts too. Mostly when there is slop in the fit of the coil in the guide. There are also cases where the slot isn't centered well enough on the hole, or the blade engages the block bending it slightly. I never really considered coil direction, but am seeing how its affects many aspects of the entire process.

The corrective action I try to apply is making sure the coil fits good in the guide, the slot and blade are centered, and adjusting feed pressure. I would like to increase to 1/128th increments, and will surely be tapering or stepping the exit.

Now back to work on my wind powered whirligig tumbler.

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Posted on Sat Jun 28, 2014 4:02 pm
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Steel... BLOCK!!!

Not sure if any person in these forums can handle such thing.

Even an aluminum block would require an "industrial" drill press.


I am not sure about the big screw. From the picture, I get the impression that the holes are through a solid wooden block, that is attached to a second wooden block underneath the first one. I though that the screw was some kind of handle.

The mandrel would work better.
There are actually two way for that.

1. A mandrel as part of a moving jig that holds the coil together. You cut by sliding the whole thing, then release the locks and you have a mandrel with cut rings.
For this, you need to cut a trench, so that the blade won't have to cut the mandrel and the rings, and the trench will also guide the blade in a straight line, which means that the trench has to be straighter than an arrow.

2. As Levi suggested, a stable, not moving mandrel, with only a notch cut at the end so that the blade will be a tad into the mandrel. You should make a sort of "coil pushing handle" to push the coil without risking loosing a finger. This will also give you feedback as to how hard you push.
The end of the mandrel should be secured on a block and you can load the mandrel either from behind by releasing it from the holding block, or from the front, by pulling the whole assembly away from the blade.
This might be more tricky to build than the first one, but I believe it would work better and will be within the abilities of most people.


In either case, the whole thing has to be stable, all the angles correct, and made of sturdy materials. Wood can be used to build a frame or something like that.

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Posted on Sat Jun 28, 2014 5:28 pm
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Spartan1388 wrote:
Steel... BLOCK!!!

Not sure if any person in these forums can handle such thing.

Even an aluminum block would require an "industrial" drill press.


He has a lathe!

I personally drill holes in steel blocks all the time, it's really not that difficult to do even with just a cordless drill, some 3in1 oil, a pair of safety glasses and a drill bit. Just this week I had to drill and tap a 7/16th hole in my lawnmower axe to reattach the wheel after getting new bearings. Had I not bottomed out the M6 tap and shattered it I would be happier but none the less, all done with the above tools.

A basic drill press on the slowest setting should work fine, most people go wrong by applying too much pressure, too much speed, not securing the piece or don't use lubricant. When you do it that way steel is a pain, otherwise it's pretty easy.

Another option given he has a lathe would be to use the lathe to drill the holes in the steel block.

Ask a small machining shop to drill a hole or two in a steel block and they'll quote you a few dollars per block along with asking how many hundred you need by 5PM that day.

All that being said I'm still suggesting the mandrel setup over a steel block but given he has a lathe it could be a quick solution for the time being.


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Posted on Sat Jun 28, 2014 8:55 pm
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Levi wrote:
Spartan1388 wrote:
Steel... BLOCK!!!

Not sure if any person in these forums can handle such thing.

Even an aluminum block would require an "industrial" drill press.


He has a lathe!

I personally drill holes in steel blocks all the time, it's really not that difficult to do even with just a cordless drill, some 3in1 oil, a pair of safety glasses and a drill bit. Just this week I had to drill and tap a 7/16th hole in my lawnmower axe to reattach the wheel after getting new bearings. Had I not bottomed out the M6 tap and shattered it I would be happier but none the less, all done with the above tools.

A basic drill press on the slowest setting should work fine, most people go wrong by applying too much pressure, too much speed, not securing the piece or don't use lubricant. When you do it that way steel is a pain, otherwise it's pretty easy.

Another option given he has a lathe would be to use the lathe to drill the holes in the steel block.

Ask a small machining shop to drill a hole or two in a steel block and they'll quote you a few dollars per block along with asking how many hundred you need by 5PM that day.

All that being said I'm still suggesting the mandrel setup over a steel block but given he has a lathe it could be a quick solution for the time being.


Yeah... Drilling holes in steel just needs time and patience... And lots of lubrication.



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Posted on Sat Jun 28, 2014 11:59 pm
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We have a mini-mill. My husband has made a ring-maker for me out of aluminum. I use a coil holder made of wood. I have no problem with lubricant being absorbed by the wood. Using lubricant made specifically for cutting metal is much better than using whatever is handy. My personal preference is water-based lubricant.


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Posted on Sun Jun 29, 2014 4:43 pm
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lorraine wrote:
We have a mini-mill. My husband has made a ring-maker for me out of aluminum. I use a coil holder made of wood. I have no problem with lubricant being absorbed by the wood. Using lubricant made specifically for cutting metal is much better than using whatever is handy. My personal preference is water-based lubricant.


What type of wood?

You can spray sealant or primer to the wood and prevent this, but the heat can cause you problems, and saw cuttings as well as the coil moving against the surface will grind this away.

Something like oak will work better than soft woods, but is better to use something equally tough as the coil, or tougher.

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Posted on Mon Jun 30, 2014 1:15 am
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Spartan1388 wrote:

What type of wood?

You can spray sealant or primer to the wood and prevent this, but the heat can cause you problems, and saw cuttings as well as the coil moving against the surface will grind this away.

Something like oak will work better than soft woods, but is better to use something equally tough as the coil, or tougher.

The coil holder is made of very hard wood. Something exotic, but I don't remember what the name is. It is harder than oak. The coil is held in place with an insert (also wooden) and this keeps the coil from rocking while being cut. There is a small plate of metal embedded at the end where the coil is up against the inside of the holder. This keeps the coil from cutting into the wood when it rotates. The blade is immersed in cutting fluid while sawing and it does not cut anything but the coil through a slit in the bottom. Over-heating of the coil holder has not been a problem for me. A metal coil holder is great, but if you cannot make it yourself, wood is a decent alternative.


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Posted on Mon Jun 30, 2014 5:23 pm
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I guess it is something like Cocobolo.

Harder woods do not absorb fluids as easily as softer woods, but generally, a polished steel rod would be a better option and some times cheaper than some hard exotic woods.

Wood cannot really "overheat", wood starts burning after a point. The problem is the coil itself. Cutting too fast, will produce heat, the coil will absorb the heat and it will transmit the heat to anything it makes contact with. If this is a wooden rod that has been stained, sealed, primed, or painted, the paint will start vaporizing, releasing fumes that are not the best thing for our health. If the wood starts "smoking" this damages the wood and also releases carbon monoxide.

A metal coil holder will act as a heat sink, while wood cannot, and you do not have to worry at all if you apply lubricant of grease on a metallic metal holder.

Wood might be more convenient, but finding an aluminum or copper pipe cannot be that hard. These are excellent heat sinks and because they are pipes you can even water cool them from the inside, which is not necessary unless you are planning on cutting rings in an industrial scale, but you have many more options than with wood.

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